In this paper, they describe the combined approach of Car and Parrinello to determine the simultaneous �on-the-fly� evolution of the (Newtonian) nuclear degrees of freedom and of the electronic wavefunctions, as implemented in a modern density-functional code based on plane-waves basis sets, and with the electron�ion interactions described by ultrasoft pseudopotentials. Lecture Notes Collection FreeScience.info ID2022 Obtained from... Topics: Molecular Dynamics, "
An introduction into the basic ideas of ab initio molecular dynamics methods is given. These methods unify molecular dynamics simulations and electronic structure calculations in the sense that the interactions, i.e. the forces used to propagate the classical nuclei, are obtained from concurrent or �on the fly� electronic structure calculations. Several such molecular dynamics schemes are discussed which arise from a sequence of approximations to the fully coupled Schr ̈odinger equation... Topics: Molecular Dynamics, "
The rapidly growing field of ab initio molecular dynamics is reviewed in the of a series of lectures. Several such molecular dynamics schemes are compared which arise from following various approximations to the fully Schrodinger equation for electrons and nuclei. Special focus is given to the Car�Parrinello method with discussion of both strengths and weaknesses in addition to its range of applicability. To shed light upon why Car�Parrinello works several alternate perspectives of the... Topics: Molecular Dynamics, "
Book digitized by Google from the library of University of California and uploaded to the Internet Archive by user tpb. Topics: Matter, Molecular dynamics Source: http://books.google.com/books?id=sFpDAAAAIAAJ&oe=UTF-8
Book digitized by Google from the library of the New York Public Library and uploaded to the Internet Archive by user tpb. Topics: Matter, Molecular dynamics Source: http://books.google.com/books?id=cHYIAAAAIAAJ&oe=UTF-8
Slides for the defense of doctoral dissertation by Kaihsu Tai; Department of Chemistry and Biochemistry, University of California, San Diego, 2002. Topics: acetylcholinesterase, fasciculin, finite element method, molecular dynamics, neuromuscular junction
This presentation discusses coupling between carbon nanotubes (CNT), simple metals (FEG) and a graphene sheet. The graphene sheet did not couple well with FEG, but the combination of a graphene strip and CNT did couple well with most simple metals. Topics: CARBON NANOTUBES, NANOINDENTATION, SILICON, ETCHING, MOLECULAR DYNAMICS, SIMULATION, CHEMICAL BONDS
byBallin, Mark G.; Hoekstra, Jacco M.; Wing, David J.; Lohr, Gary W
Distributed Air/Ground Traffic Management (DAG-TM) is a concept of future air traffic operations that proposes to distribute information, decision-making authority, and responsibility among flight crews, the air traffic service provider, and aeronautical operational control organizations. This paper provides an overview and status of DAG-TM research at NASA Langley Research Center and the National Aerospace Laboratory of The Netherlands. Specific objectives of the research are to evaluate the... Topics: CARBON NANOTUBES, STRAIN RATE, WALLS, ESTIMATING, MOLECULAR DYNAMICS, SIMULATION
The metadata below describe the original scanning. Follow the "All Files: HTTP" link in the "View the book" box to the left to find XML files that contain more metadata about the original images and the derived formats (OCR results, PDF etc.). See also the What is the directory structure for the texts? FAQ for information about file content and naming conventions. Topics: Matter, Molecular dynamics, Kinetic theory of gases, Liquids
A new infrared heterodyne instrument has been developed which allows the use of both tuneable diode lasers (TDL) and quantum cascade lasers (QCL) as local oscillators (LO). The current frequency tuning range of our system extends from 900 to 1100/cm depending on the availability of lasers but is planned to be extended to 600/cm soon. The IF-bandwidth is 1.4 GHz using an acousto-optical spectrometer (AOS). The frequency resolution and stability of the system is approximately 10(exp 7).... Topics: CARBON NANOTUBES, CONTINUUM MODELING, CROSSLINKING, MOLECULAR DYNAMICS, THERMODYNAMICS
bySeiner, John M.; Backley, Floyd D.; Gilinsky, Mikhai
A Mobius strip concept is intended for improving the working efficiency of propellers and screws. Applications involve cooling, boat propellers, mixing in appliance, blenders, and helicopters. Several Mobius shaped screws for the average size kitchen mixers have been made and tested. The tests have shown that the mixer with the Mobius shaped screw pair is most efficient, and saves more than 30% of the electric power by comparison with the standard. The created video film about these tests... Topics: CARBON, NANOTECHNOLOGY, NANOTUBES, ARCHITECTURE (COMPUTERS), COMPUTERS, WIRE, MOLECULAR DYNAMICS
Book digitized by Google from the library of the University of Michigan and uploaded to the Internet Archive by user tpb. Topics: Matter, Molecular dynamics, Kinetic theory of gases, Liquids Source: http://books.google.com/books?id=muc5AAAAMAAJ&oe=UTF-8
Doctoral dissertation by Kaihsu Tai; Department of Chemistry and Biochemistry, University of California, San Diego, 2002. (ISBN 0-493-90932-X) Topics: acetylcholinesterase, fasciculin, finite element method, molecular dynamics, neuromuscular junction
bySanders, Albert J.; Liu, Jong S.; Panovsky, Josef; Bakhle, Milind A.; Stefko, George; Srivastava, Rakes
Flutter-free operation of advanced transonic fan designs continues to be a challenging task for the designers of aircraft engines. In order to meet the demands of increased performance and lighter weight, these modern fan designs usually feature low-aspect ratio shroudless rotor blade designs that make the task of achieving adequate flutter margin even more challenging for the aeroelastician. This is especially true for advanced forward swept designs that encompass an entirely new design space... Topics: MOLECULAR DYNAMICS, CARBON NANOTUBES, BONDING, ROTATION, STABILITY, METASTABLE STATE
Book digitized by Google from the library of the University of California and uploaded to the Internet Archive by user tpb. Topics: Matter, Molecular dynamics, Kinetic theory of gases, Liquids Source: http://books.google.com/books?id=ngFJAAAAIAAJ&oe=UTF-8
NASA's Advanced Architectures and Automation Branch at the Goddard Space Flight Center (Code 588) saw the potential to reduce the cost of constellation missions by creating new user interfaces to the ground system health-and-safety data. The goal is to enable a small Flight Operations Team (FOT) to remain aware and responsive to the increased amount of ground system information in a multi-spacecraft environment. Rather than abandon the tried and true, these interfaces were developed to run... Topics: CARBON NANOTUBES, MECHANICAL PROPERTIES, MOLECULAR DYNAMICS, ELECTRONIC STRUCTURE, PLASTIC...
NASA's goal of safe, affordable space transportation calls for increased reliability and lifetimes of launch vehicles, and significant reductions of launch costs. The areas targeted for enhanced performance in the next generation of reusable launch vehicles include combustion chambers and nozzle ramps; therefore, the search is on for suitable liner materials for these components. GRCop-84 (Cu-8Cr-4Nb), an advanced copper alloy developed at the NASA Glenn Research Center in conjunction with Case... Topics: POLYIMIDES, FIELD THEORY (PHYSICS), MODULUS OF ELASTICITY, ELASTOPLASTICITY, SHEAR STRENGTH, ATOMIC...
We present test results of the first adiabatic demagnetization refrigerator (ADR) that can produce continuous cooling at sub-kelvin temperatures. This system uses multiple stages that operate in sequence to cascade heat from a continuous stage up to a heat sink. Continuous operation aids the usual constraints of long hold times and short recycle times that lead to the generally large mass of single-shot ADRs, and allows us to achieve much higher cooling power per unit mass. Our design goal is... Topics: THERMODYNAMICS, NANOTECHNOLOGY, MOLECULAR DYNAMICS, SURFACE LAYERS, GOLD, THERMAL EXPANSION, FAST...
byWilson, J. W.; Tripathl, R. K.; Cicomptta, F. A.; Heinbockel, J. H.; Tweed, J
High-speed computational procedures for space radiation shielding have relied on asymptotic expansions in terms of the off-axis scatter and replacement of the general geometry problem by a collection of flat plates. This type of solution was derived for application to human rated systems in which the radius of the shielded volume is large compared to the off-axis diffusion limiting leakage at lateral boundaries. Over the decades these computational codes are relatively complete and lateral... Topics: THERMODYNAMICS, PHYSICAL CHEMISTRY, SILICON COMPOUNDS, HYDROXYL COMPOUNDS, MOLECULAR DYNAMICS,...
The X-38 is an experimental NASA project developing a core human capable spacecraft at a fraction of the cost of any previous human rated vehicle. The first operational derivative developed from the X-38 program will be the International Space Station (ISS) Crew Return Vehicle (CRV). Although the current X-38 vehicles are designed as re-entry vehicles only, the option exists to modify the vehicle for uses as an upward vehicle launched from an expendable launch vehicle or from the X-33... Topics: FOLDING, TRAJECTORIES, WATER, MOLECULAR DYNAMICS, PEPTIDES, RESEARCH, SIMULATION, ADSORPTION, FREE...
The tapered element oscillating microbalance (TEOM), an ultrasensitive mass measurement device which is suitable for both particulate and vapor deposition measurements is described. The device can be used in contamination measurements, surface reaction studies, particulate monitoring systems or any microweighing activity where either laboratory or field monitoring capability is desired. The active element of the TEOM consists of a tube or reed constructed of a material with high mechanical... Topics: LOW COST, SILICON, SOLAR ARRAYS, CARBON, COMPUTER PROGRAMS, FREE ENERGY, MOLECULAR DYNAMICS,...
byBerchem, Jean; Savin, S.; Zelenyi, L., et al; Nemecek, Z.; Safrankova, J.; Prech, L.; Simunek, J.; Sauvaud, J.-A.; Fedorov, A.; Stenuit, H.; Fuselier, S. A.
The cusp represents a place where the magnetosheath plasma can directly penetrate into the magnetosphere. Since the main transport processes are connected with merging of the interplanetary and magnetospheric field lines: the interplanetary magnetic field (IMF) Orientation plays a decisive role in the formation of the high-altitude cusp. The importance of the sign of the IMF B(sub Z) component for this process was suggested about 40 years ago and later it was documented by many experimental... Topics: BORON NITRIDES, NANOTUBES, MOLECULAR DYNAMICS, AMORPHOUS MATERIALS, STABILITY, SEMICONDUCTORS...
byHarris, J. D.; Raffaelle, R. P.; Banger, K. K.; Smith, M. A.; Scheiman, D. A.; Hepp, A. F
Solar cells have been prepared using atmospheric pressure spray chemical vapor deposited CuInS2 absorbers. The CuInS2 films were deposited at 390 C using the single source precursor (PPh3)2CuIn(SEt)4 in an argon atmosphere. The absorber ranges in thickness from 0.75 - 1.0 micrometers, and exhibits a crystallographic gradient, with the leading edge having a (220) preferred orientation and the trailing edge having a (112) orientation. Schottky diodes prepared by thermal evaporation of aluminum... Topics: MULTISCALE MODELS, COMPUTERIZED SIMULATION, MOLECULAR DYNAMICS, QUANTUM MECHANICS, PARALLEL...
byBernstein, Max P.; Elsila, Jamie E.; Dworkin, Jason P.; Sandford, Scott A.; Allamandola, Louis J.; Zare, Richard N
Ultraviolet photolysis of various ice mixtures at low temperature and pressure caused the addition of amino (-NH2), methyl (-CH3), methoxy (-OCH3), and cyano (-CN) functional groups to the polycyclic aromatic hydrocarbon (PAH) coronene (C22H12). The implications of these results for interstellar and meteoritic chemistry are discussed. Previously only simple PAH photo-oxidation had been reported. This work represents the first experimental evidence that ice photochemistry may have contributed to... Topics: BORON NITRIDES, COMPOSITE MATERIALS, CARBON NANOTUBES, COMPUTERIZED SIMULATION, MOLECULAR DYNAMICS,...
The effect of thermal diffusively on the defect detectability in Carbon/Epoxy composite panels by transient thermography is presented in this paper. A series of Finite Element Models were constructed and analyzed to simulate the transient heat transfer phenomenon during Thermographic Non-destructive Evaluation (TNDE) of composite panels with square defects. Six common carbon fibers were considered. The models were built for composites with various combinations of fibers and volumetric ratios.... Topics: MOLECULAR DYNAMICS, RADIAL DISTRIBUTION, ENERGY DISTRIBUTION, ALANINE, PEPTIDES, WATER, GLYCEROLS,...
byLoughlin, James P.; Fettig, Rainer K.; Moseley, S. Harvey; Kutyrev, Alexander S.; Mott, D. Bren
Finite element models have been created to simulate the electrostatic and electromagnetic actuation of a 0.5 micrometers silicon nitride micro-shutter for use in a spacebased Multi-object Spectrometer (MOS). The microshutter uses a torsion hinge to go from the closed, 0 degree, position, to the open, 90 degree position. Stresses in the torsion hinge are determined with a large deformation nonlinear finite element model. The simulation results are compared to experimental measurements of... Topics: CARBON NANOTUBES, STRAIN RATE, TEMPERATURE DEPENDENCE, TENSILE STRENGTH, MOLECULAR DYNAMICS,...